Python Instance variables are variables that have their unique value to a particular instance. The instance variables are owned by an instance (Object) of a class. They are declared inside a class method.
Example instance variable in Python
Simple example code student class example below, name and age are instance variables:
class Student:
def __init__(self, name, age):
self.name = name
self.age = age
s1 = Student('John', 18)
s2 = Student('Tim', 70)
print(s1.name)
print(s2.name)Output:
Different ways to access Instance Variable in Python
Using Self and object reference
class Student:
def __init__(self, name, age):
# instance variable
self.name = name
self.age = age
def display(self):
# using self to access variable inside class
print("Name:", self.name, "Age:", self.age)
s1 = Student('John', 18)
s2 = Student('Tim', 70)
s1.display()
s2.display()
Output:
Name: John Age: 18
Name: Tim Age: 70
Using getattr()
class Student:
def __init__(self, name, age):
# instance variable
self.name = name
self.age = age
def display(self):
# using self to access variable inside class
print("Name:", self.name, "Age:", self.age)
s1 = Student('John', 18)
s2 = Student('Tim', 70)
print(getattr(s1, 'name'))
print(getattr(s2, 'name'))Output:
John
Tim
Do comment if you have any doubts or suggestions on this Python variable topic.
Note: IDE: PyCharm 2021.3.3 (Community Edition)
Windows 10
Python 3.10.1
All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.